| (19) |
 |
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(11) |
EP 0 348 036 A3 |
| (12) |
EUROPEAN PATENT APPLICATION |
| (88) |
Date of publication A3: |
|
27.03.1991 Bulletin 1991/13 |
| (43) |
Date of publication A2: |
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27.12.1989 Bulletin 1989/52 |
| (22) |
Date of filing: 11.05.1989 |
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| (84) |
Designated Contracting States: |
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DE ES FR GB IT |
| (30) |
Priority: |
20.06.1988 US 209111
|
| (71) |
Applicants: |
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- Hughes Aircraft Company
Los Angeles, California 90045-0066 (US)
- Santa Barbara Research Center
Goleta
California 93117 (US)
- DELCO ELECTRONICS CORPORATION (a Delaware corp.)
Kokomo, Indiana 46902 (US)
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| (72) |
Inventors: |
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- May, Phillip A.
Lompoc
California 93436 (US)
- Dunn, Douglas L.
Bellflower
California 90706 (US)
- Wen, Cheng P.
Mission Viejo
California 92691 (US)
- Ferry, Stephen J.
Santa Barbara
California 93111 (US)
|
| (74) |
Representative: Denton, Michael John |
|
Patent Section
1st Floor
Gideon House
28 Chapel Street
Luton
Bedfordshire LU1 2SE
Luton
Bedfordshire LU1 2SE (GB) |
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| |
|
| (54) |
Narrow bandwith frequency modulated radar apparatus for obstacle detection |
(57) In a radar apparatus, an RF signal is transmitted at a frequency modulated by a sawtooth
signal. The transmitted RF signal is mixed with the transmitted signal reflected from
an object. The resulting IF signal is analyzed into a Fourier series having a DC coefficient
and harmonic frequency coefficients. The range to the object is determined from the
harmonic frequency coefficients in multiples of the range resolution determined by
the RF bandwidth of the apparatus when the DC coefficient is less than-each of the
harmonic frequency coefficients. The range to the object is determined to be within
1/2 the range resolution determined by the RF bandwidth when the DC coefficient is
greater than each of the harmonic frequency coefficients.